Follow the River Wandle from where it joins the Thames back to its source near Croydon in South London. This route is mostly quiet cycle paths, with plenty of options for stops and exploring along the way.
We'd recommend taking some time at Merton Abbey Mills, where there's a range of craft shops, places to eat, and the William Morris pub on the river. There's also Deen City Farm, which offers free entry to see the Alpacas, and Morden Hall Park for a picnic.
While you can do this route in either direction, finishing at West Croydon Station gives you better onward transport options.